Fuse contact cleaning device



J. c. RODRIQUEZ 2,503,299 I FUSE CONTACT CLEANING DEVICE April 11, 1950 Filed Feb. 21, 1945 Inventor My Attorneys Patented Apr. 11, 1950 UNITED STATES PATENT OFFICE FUSE CONTACT CLEANING DEVICE Julius C. Rodriquez, Los Angeles, Calif. Application February 21, 1945, Serial No. 579,047

1 Claim. 1

This invention relates to the reconditioning of electric contacts on which a poorly conducting layer has formed and it has for its main object to provide a simple eilective and handy device adapted to recondition contacts not easily accessible, such as the center contacts of fuses, connectors and the like, enclosed within and arranged in the interior or at the bottom of a threaded sleeve contact while under tension.

The invention mainly consists in a device provided with reconditioning means such as an abrasive wiper, adapted to remove a superficial coating of the contact to be cleaned, which is arranged within a plug, body or holder, built exactly in the manner of the plug or bodyof a fuse connector or the like and adapted to be seated on and connected with the electric contacts one of which is to be reconditioned. The insertion and seating of said plug or holder brings the wiper into its operative position, required for reconditioning.

Means are moreover provided on the outside, duly insulated from current carrying parts in contact with live contacts, which permit cleansing or wiping of the contact while under electric tension.

Further and more specific objects of the invention will be apparent from the following detailed specification, describing and illustrating one embodiment thereof. It is however to be understood that the specification explains the constructive principles on which the invention is based by way of referring to an example and does not attempt to provide a summary of the modifications which may embody the invention. Modifications of the example shown are therefore not necessarily departures from the invention.

In the following there is described the general embodiment of the invention the features thereof being more clearly defined hereinafter in the claim appended hereto.

In the drawings:

Figure 1 is a side elevation of the screw plu a socket therefor being shown in vertical section to illustrate an application of the invention.

Figure 2 is a vertical sectional view of the composite structure of the screw plug on the line 2-2 of Figure 1 of the drawing.

Figure 3 is an elevation of the support button of the abrasive wiper means of the device.

Figure 4 is an elevation of the screw plug casmg.

Figure 5 is an elevation of the expansive spring employed as the pressing means for said abrasiv wiper.

Figure 6 is a side elevation of the abrasive supporting member showing the means therein of mounting same on said button and of the mounting thereon of the abrasive or grinder head employed as the contact wiper means of the structure, and

Figure 7 is a plan view of the screw plug casing showin its serratiform perimeter, and of the positions therein of the actuator button of said contact wiper or grinder means therefor.

Standardized contacts such as those used for;

the reception of fuses, electric lamps, connectors for cords, etc., and several other types of contests are customarily provided with a threaded (or slotted) sleeve forming one contact and with a center terminal or button forming the second contact. The surface of the latter is small and contact is made with it by pressing down the center contact of the appliance to be inserted into the circuit which is mounted within a suitable plug fitting into the sleeve. This contact system, if handled carelessly, leads to an imperfect contact between the two center contacts which may cause arcing or sparking during operation. Arcs or sparks in their turn cause a permanent deterioration of the central contact in two ways. One of the causes of deterioration consists in oxidation of the contact at the points at which the are or spark passes while the other consists in so called pitting or formation of small point like grooves, due to the transportation of material away from this spot during arcing or sparking.

Both phenomena reduce the conductivity of the contact or, expressed otherwise, increase the contact resistance by reducing the area of perfect conduction. As careless manipulation may sometimes not be detected for an appreciable time, the resistance of the contact may increase to such an extent that overheating occurs.

According to the invention the conductive area of such center contacts may be completely restored while these contacts are under electric tension and without any disassembling or dismounting operation other than the removal of the appliance which caused the imperfect contact from the sleeve.

In Figure 1, i0 designates the customary standardized sleeve contact socket of the so called Edison type. This socket comprises, in addition to an insulating base, a threaded sleeve and center terminal or button l6. Into this socket any appliance may be screwed, which is provided with corresponding contacts. The device according to the invention comprises a plug I2 of insulating material provided with a threaded shell ll fitting into the threaded sleeve of the socket. This plug is the carrier for an abrasive wiping device which serves to clean or wipe the central contact 16 of the socket.

For this purpose the plug 12 is provided with a cylindrical bore I3 into which a cylindrical rod I! of insulating material is inserted. This rod carries on one end a sleeve l8 threaded inter-V nally to receive the threaded end 19 of the stem '20 which projects through an aperture I5 in the top of the plug and has mounted on its outer end a button 2| of insulating material provided with a gripping hexagonal core 22. Said rod and core are coupled for rotation by means of the spanner" end 23.

Said rod I1 is slotted at 24 and has mounted therein on a key 25 a metallic abrasive and wiper" 4 knob 26 or a knob made of Carborundum or of a similar abrasive material. A compression spring is provided around stem 20 between rod l1 and the top of easing I2, its tension being adjusted by means of either tightening or loosening the relative mounting thereof in sleeve l'8.

The screw-plug wiper is inserted in the defective socket or plug-in device in the customary manner until the elements are seated, whether or not the contacts of the socket are under tension. The button 2| and head 22 are turned or rotated to cause abrader head 26 to wipe the contact point I6, and due to such rotative motion and to the abrasive properties of the head 26 carried by the rod 11 the contact I6 is thoroughly cleaned and polished. Thereby the original condition of the contact surface and itsoriginal conductivity is restored.

It is to be understood that the structure and its method of assembly and fabrication may be altered in many ways without departing from the spirit of the invention.

What I claim is:

A device for resurfacing the central contacts of sockets for electrical appliances, comprising a cylindrical plug body of insulating material provided with an axial central opening, a threaded shell surrounding the same, a rotatable and slidable supporting member'having a female threaded aperture in its upper portions thereof housed within said opening in bearing engagement with the inner walls of said plug, an abrasive head secured to said supporting member and rotatable therewith, a rotatable knob of insulating material projecting on the other side of the plug and means i for coupling said knob with said rotatable sup- "porting member, said means comprising a connecting member having one end encompassed by said knob, and having its other end in threaded engagement within said female aperture with said supporting member.

JULIUS C. RODRIQUEZ.

REFERENCES CITED The following references are of record in the file of thispatent:

UNITED STATES PATENTS Number Name Date 352,591 Tower Nov. 16, 1886 692,459 Langlois Feb. 4, 1902 1,801,731 Farrington Apr. 21, 1931 2,076,998 Martindale et al. Apr. 13, 1937 2,309,765 Haase Feb.,2, 1943 2,357,038 Whitesell Aug. 29, 1944 

